XML Unleashed

Entities and Document Structure

An XML document is divided into storage units, called entities, that are usually identified by unique names. One entity in particular that isn't identified by name is the document entity, which is the top-level entity for a document. The document entity typically contains the entire document. This may seem strange until you consider that entities are broken down into subentities, which are often broken down further. The breakdown of entities ends when you arrive at nothing but content.

Entities define the physical structure of documents, so they are often associated with files. In reality, many entities correspond to physical files located on file systems somewhere (locally or on a network). However, entities ...